(19)
(11) EP 0 798 463 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
25.02.1998 Bulletin 1998/09

(43) Date of publication A2:
01.10.1997 Bulletin 1997/40

(21) Application number: 97105399.6

(22) Date of filing: 01.04.1997
(51) International Patent Classification (IPC)6F04C 18/02, F04C 29/04, F04C 29/08, F04C 29/10
(84) Designated Contracting States:
DE FR GB IT

(30) Priority: 29.03.1996 JP 103431/96
29.03.1996 JP 104192/96

(71) Applicant: Anest Iwata Corporation
Tokyo 150 (JP)

(72) Inventors:
  • Tsuchiya, Masaru
    Yokohama-shi, Kanagawa, 234 (JP)
  • Haga, Shuji
    Yokohama-shi, Kanagawa, 230 (JP)

(74) Representative: Strehl Schübel-Hopf Groening & Partner 
Maximilianstrasse 54
80538 München
80538 München (DE)

   


(54) Oil-free scroll vacuum pump


(57) A double-lap oil-free scroll vacuum pump is disclosed, which comprises a revolving scroll 3 with revolving laps 26 and 27 provided on both sides of a disc, stationary scrolls provided on their surfaces 4b, 5b facing each surface 3d, 3e of said disc with stationary laps 6, 7 in engagement with the revolving laps 26, 27, said revolving laps 26, 27 being arranged in frictional contact with said surfaces 4b, 5b of the stationary scrolls, and a rotationary drive shaft 11 penetrating the stationary and revolving scrolls and eccentrically fitted in the disc of the revolving scroll 3, wherein the rotational drive shaft 11 drives the revolving scroll 3 to cause discharge of compressed gas from a last compression chamber. A housing 19 is mounted on the outer sides of the stationary scrolls, and accommodates a drive source of the rotational drive shaft 11. Discharge passages 4d and 5d are provided for discharging compressed gas from the sides of the surfaces 3d and 3e of the revolving scroll 3. The discharge passages 4d and 5d extend outwardly from the housing 19.







Search report